Photography tidbits

This page contains some tidbits related to photography.

Based on the amount of megapixels and the aspect ratio of an image sensor you can calculate the dimensions of the images produced by the camera.

Keep in mind that these calculations are estimations. Of all the cameras I've used in the past years only a few had, when dividing the amount of horizontal pixels of the sensor by the amount of vertical pixels, the exact aspect ratio of 1 : 1.5. Usually it was a few digits after the decimal point more or less.
For example the Nikon Z6, which was marketed as a 24.5 megapixel camera, has an images sensor of 4024 pixels high and 6048 pixels wide. Dividing 6048 by 4048 results in an actual aspect ratio is 1.5029821074 : 1. Multiplying both numbers gives you the actual megapixel count: 24.337.

Most common aspect ratio's of image sensors:
- 1 : 1 - square photos
- 1.5 : 1 - DSLR and 35mm film cameras
- 1.333 : 1 - typical for compact cameras and cell phone cameras
- 1.778 : 1 - HDTV and camera video

The calculation:
H = SQR ( MP / AR )
W = Height * AR
(where AR is the aspect ratio, MP is the amount of megapixels and H and W are the height and width of the image respectively)

For the marketed 24.5 megapixels of the Nikon Z6 the calculation would be as follows:
Hight = SQR ( 24.5 / 1.5 ) = 4,041 pixels
W = 4.041 * 1.5 = 6,062 pixels
Very close to the actual dimensions of the images sensor.